Decat & downpipe question

[AD1.8T]

Soo my mot is next month and i plan on getting a 3" downpipe and decat to throw on after i get my piece of paper but.... I have an aum 1.8t so as you all know has the 2 sensors, obviously when i put it on the car is not going to like it! Now, does it just bring up the engine light or will it go into limp mode/roll over and die ? I dont plan on getting it mapped untill well im not sure when but not within the next 6 months is there any other way to stop the light coming on or is getting it mapped out the only way ?

Also when its been mapped out does it then throw a wobbler if you put the cat back on for mot purposes?

And finally i dont plan on getting a decent cat back unless one comes up for cheap so it will be going on my tdi centre section then to the standard B.B can anyone point me in the right direction as to which one to get as theres quite a few different sizes on ebay and im a bit confused. If i got a 3" i would then need a 3" - 2 1/4" reducer ?? Not sure .....
 

[Scott D]

had one on for a few weeks now no warning lights or fault codes have appeared and not using any spacers for the lambda either.

[beppe2672]

I've got a right angle lambda sensor spacer for mine, and I have no codes. It also makes fitting the lambda sensor easier as it lays flat against the decat pipe.

[AD1.8T]

had one on for a few weeks now no warning lights or fault codes have appeared and not using any spacers for the lambda either.

Hmmm thats kind of annoying as ive read alot that its abit hit and miss ! Do you have a link to the one you brought ?

[AD1.8T]

I've got a right angle lambda sensor spacer for mine, and I have no codes. It also makes fitting the lambda sensor easier as it lays flat against the decat pipe.

You have an agu bud they can get away with them with no problems i believe im interested in this spacer thing though where did you get it from ?

[davemk4]

ebay sell em and so do awesome gti. my customer 3'' decat after about 3 week caused light to come on then fitted a spacer and all is good so far. light comes on sometimes then goes off

[Scott D]

milltek pipe from awesome gti

was amazed they had it in stock and same price as ebay sellers.

would of bought a toyosports but already had a milltek cat back

[dom]

I'm running 3" downpipe & decat and have been for about a year, I've had no problems with warning lights etc. To join it to a standard cat-back system will be an issue, most 2.25" pipe won't flare to 3" so you'll struggle to get a reducer made up that doesn't involve you chopping into your centre pipe.

[AD1.8T]

See theres this one which says end pipe fits to 2.5" and 2.25" so that will go straight on ?

Item number 150832272345

[GTi_James]

I'm running 3" downpipe & decat and have been for about a year, I've had no problems with warning lights etc. To join it to a standard cat-back system will be an issue, most 2.25" pipe won't flare to 3" so you'll struggle to get a reducer made up that doesn't involve you chopping into your centre pipe.

what type engine you running? AUM's are picky to say the least, i should be doing this end of the month hopefully!